How to Switch animations and Stealth Horror Mechanics - 3D First Person Horror

I had a 3D Model for a character but I wanted to switch animations. For when he falls, when he jumps, when he catches you, when he runs, when he’s in his idle mode. I also wanted to know how to make him just wander around his house but when he notices you he chases you and when you are in an area he can’t get to, he gives up finding you.